It aims at development of the safe recombination oral vaccine, half-oral vaccine and a new delivery vector by the new reverse genetics method which we established and which rearranges and makes development of a recombinant Morbilli virus possible in this research. This fiscal year mainly performed fundamental analysis of a virus vector using the rinderpest virus (RPV). First, it suggested that P protein was greatly concerned with the pathogenical change. when exchange the host using the RBOK and L strain of RPV. Moreover, to virus protein which governs pathogenicity was solved. Virus cloning established the highly pathogenic RPV-Lv strain and the weak pathogenic RPV-La strain out of the RPV-L strain. Consequently, among both, the amino acid substitution per site was found out in N, P, C, and L protein. When analyzed using seven sorts of viruses which rearranged the variation of N, P, and L genes of La strain with L strain, independently or simultaneous using the reverse genetics system
… More, clinical condition was mitigated only for what changed N gene to La strain type. It became clear that N protein is important for pathogenesis of L strain. Moreover, in the B95a cell, although the vector which makes conditional expression system of M gene using a Cre/loxP system was produced for half-oral vaccine production, since the cell strain could nott be established. H gene mutated measles (MV) vector was tried to established, but a rescue was not succeeded, therefore, the new receptor binding unit which. is containing the penetration domain of the antibody recognition part gene (Fv) was induced in MV vector. They were obtained and analyzing whether an infection capacity has been changed. Furthermore, in order to analyze easily the delivery vector, the virus incorporating GFP and the luciferase gene was produced using the canine distemper virus (CDV) and MV vector. Among these, it succeeded in a MV-GFP vector visualizing the nerve cells which used the in vivo imaging equipment after inoculation in the mouse brain. Less